This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A relatively new type of O-linked glycan has been implicated in neuronal cell adhesion and migration, the O-linked mannose glycans. This project will use novel techniques to separate glycoproteins expressing O-Man glycans from brain tissue and identify these glycoproteins using mass spectrometry techniques. In addition, the Asn-linked glycans from mouse brain have been identified by MALDI-TOF MS. These are being compared to glycans found in mice that are null for the GnT-Va glycosyltransferase to determine how this enzyme regulates glycoprotein glycan expression. A GnT-Vb null mouse has now been produced and the effects of this deletion on O-Man and Asn-linked glycoproteins is now under study.